Power consumption optimization on the cloud

ABSTRACT

A power consumption optimization system includes a virtual machine (VM) provisioned on a host, a memory, a server, and a processor in communication with the memory. The processor causes the server to store a power consumption profile of the VM. The VM runs at a processor frequency state. Additionally, the processor causes the server to receive a request to lower a processor frequency for the VM from an original processor frequency state to a reduced processor frequency state. The request has request criteria indicating a time duration associated with the request. The server validates the request criteria and a requirement of another tenant on the host. Responsive to validating the request criteria and the requirement the other tenant on the host, the server confirms the request to lower the processor frequency. Additionally, the server lowers the processor frequency to the reduced processor frequency state during the time duration.

BACKGROUND

Computer systems may run applications and processes that execute variousinstructions on a processor. Processors may execute instructions atvarious performance levels based on the processors frequency and/or thevoltage supplied to the processor. For example, processors may operateat a specified power state or P-state, which may be a defined frequencyvoltage pair for that processor. The power consumption, and therefore,the operating costs associated with running applications on the cloudmay be directly linked to the P-state of the processors used to executetasks and commands associated with the applications. For example, eachP-state may have a designated operating cost or price per hour. Highperformance power states have higher frequencies and voltages than lowerperformance power states, but due to the higher voltage, these higherperformance power states may consume more power and thus are associatedwith higher operating costs.

SUMMARY

The present disclosure provides new and innovative systems and methodsfor power consumption optimization on the cloud. In an example, a systemincludes a virtual machine (VM) provisioned on a host, a memory, aserver, and at least one processor in communication with the memory. Theat least one processor causes the server to store a power consumptionprofile of the virtual machine provisioned on the host. The virtualmachine provisioned on the host runs at a processor frequency state.Additionally, the at least one processor causes the server to receive arequest to lower a processor frequency for the virtual machine from anoriginal processor frequency state to a reduced processor frequencystate. The request has request criteria indicating a time durationassociated with the request. The at least one processor also causes theserver to validate the request criteria, validate at least onerequirement of at least one other tenant on the host, and responsive tovalidating the request criteria and the at least one requirement of theat least one other tenant on the host, confirm the request to lower theprocessor frequency. Additionally, the server lowers the processorfrequency to the reduced processor frequency state during the timeduration.

In an example, a method includes storing, by a server, a powerconsumption profile of a virtual machine provisioned on a host. Thevirtual machine provisioned on the host runs at a processor frequencystate. Additionally, the server receives a request to lower a processorfrequency for the virtual machine from an original processor frequencystate to a reduced processor frequency state. The request has requestcriteria indicating a time duration associated with the request. Theserver validates request criteria and at least one requirement of atleast one other tenant on the host. Responsive to validating the requestcriteria and the at least one requirement of the at least one othertenant on the host, the server confirms the request to lower theprocessor frequency. Additionally, the server lowers the processorfrequency to the reduced processor frequency state during the timeduration.

In an example, a non-transitory machine readable medium stores code,which when executed by a processor, causes a server to store a powerconsumption profile of a virtual machine provisioned on a host. Thevirtual machine provisioned on the host to run at a processor frequencystate. The server receives a request to lower a processor frequency forthe virtual machine from an original processor frequency state to areduced processor frequency state. The request has request criteriaindicating a time duration associated with the request. The server alsovalidates the request criteria and at least one requirement of at leastone other tenant on the host. Responsive to validating the requestcriteria and the at least one requirement of the at least one othertenant on the host, the server confirms the request to lower theprocessor frequency. Additionally, the server lowers the processorfrequency to the reduced processor frequency state during the timeduration.

Additional features and advantages of the disclosed method and apparatusare described in, and will be apparent from, the following DetailedDescription and the Figures. The features and advantages describedherein are not all-inclusive and, in particular, many additionalfeatures and advantages will be apparent to one of ordinary skill in theart in view of the figures and description. Moreover, it should be notedthat the language used in the specification has been principallyselected for readability and instructional purposes, and not to limitthe scope of the inventive subject matter.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a block diagram of an example cloud computing systemaccording to an example embodiment of the present disclosure.

FIG. 2 illustrates a flowchart of an example process for powerconsumption optimization according to an example embodiment of thepresent disclosure.

FIGS. 3A, 3B, and 3C illustrate a flow diagram of an example process forpower consumption optimization on the cloud according to an exampleembodiment of the present disclosure.

FIG. 4 illustrates a block diagram of an example power consumptionoptimization system according to an example embodiment of the presentdisclosure.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Techniques are disclosed for providing power consumption optimization onthe cloud. Currently, techniques of reducing processor frequency atruntime are typically used in mobile and desktop devices. For example,frequency scaling may typically involve monitoring battery capacity orsystem temperature and reducing processor performance (e.g., frequencyand/or voltage) to increase battery life, reduce heat output, and/orallow quieter operation of the system (e.g., system cooling fans may bethrottled down or turned off thereby reducing noise levels). However,due to technical and scheduling limitations, neither public cloud norprivate cloud products provide mechanisms or incentives for applicationsto scale processor (e.g., CPU) frequencies to adjust power consumption.Typically, a cloud user pays a cloud provider for a set range ofperformance or power state, which may be a locked range (e.g., theoperating cost to the cloud user is the same even if the user usesscales frequency down and consumes less power). Because operating costsare typically locked for cloud users, the cloud users currently are notincentivized to reduce power consumption of applications and services onthe cloud. A cloud provider is a company that offers some component ofcloud computing, typically infrastructure as a service (IaaS), softwareas a service (SaaS), or platform as a service (PaaS) to cloud users. Acloud provider may also be referred to as a cloud service provider.

As discussed in the various example embodiments disclosed herein, toimprove efficiency and conserve resources (e.g., power consumption) forsystems with varying processor capabilities, a power consumptionoptimization system may receive and store power consumption profilesfrom cloud users, which indicate power consumption requirements of avirtual machine provisioned on a host. The power consumption profile mayindicate the range of frequencies that are acceptable for the virtualmachine. Then, the virtual machine may be provisioned on an appropriatehost (e.g., a host capable of operating in the processor frequency rangerequired by the virtual machine). Cloud users may submit requests to thecloud provider to lower a processor frequency for the virtual machine(e.g., application or service running on virtual machine) from anoriginal frequency to a reduced frequency during a specific time period.For example, a cloud user may provide and/or use a cloud applicationmainly during working hours, but the application may not receive as muchtraffic outside of work hours, and a lower processor frequency (and thuslower power consumption) may be capable of handling the workload for theapplication during that time. Due to this decreased workload outside ofwork hours, the cloud user may submit the request to reduce thefrequency during this time period, and in the request they may include arange of acceptable incentives, such as a cloud credit demand.

Then, the request may be validated if the host is capable of operatingat the requested processor frequency range, the request is compatiblewith other tenants (e.g., virtual machines) on the host, and theincentive (e.g., cloud credit demand) is reasonable. For example, thecloud credit demand may be reasonable if it is within an operating costdifference between instance types that run close to the target orrequested CPU frequency and the current instance type. For example, arequest to lower CPU frequency from a power state or P-state P0 to P2may be validated if the incentive or demand is within the costdifference of P0 and P2. After the request is validated, the request maybe honored or confirmed and the cloud user may receive cloud credits.Cloud credits may be used to scale-up CPU frequency, for example, when acloud user experiences a spike in demand due to an unexpected orforecasted increase in workload.

Instead of the processor constantly operating at the same frequencythereby wasting computer resources and consuming additional power duringlow demand periods and failing to meet workload demands during spikes inapplication traffic, the cloud user may request to reduce processorfrequency to a lower frequency state during certain time periods toobtain cloud credits which may be used to increase processor performanceduring demand spikes, which advantageously allows the processor tooptimally complete task under various workload conditions. Reducing theprocessor frequency advantageously conserves resources, improves theefficiency of the processor, reduces power consumption, decreases heatgeneration, and may extend the life of a hardware processor and/orreduce requirements for external cooling of hardware (e.g., in adatacenter).

FIG. 1 depicts a high-level component diagram of an example cloudcomputing system 100 in accordance with one or more aspects of thepresent disclosure. The cloud computing system 100 may include anoperating system (e.g., host OS 186), one or more virtual machines (VM170A-B), hosts (e.g., hosts 110A-C), a server 160, and a hypervisor(e.g., hypervisor 180).

The server 160 may include an application program interface (API) 162.In an example, the server 160 may serve as an interface between a clouduser (e.g., user implementing virtual machines 170A-B on the cloud) anda cloud provider. The server 160 may store power consumption profiles191A-B received from cloud users. The server 160 may also receiverequest from cloud users to lower a processor frequency or power statefor the virtual machine (e.g., lower the processor frequency of the host110 that the virtual machine 170A-B is provisioned on). The request mayindicate a target reduced processor frequency state, a start time forthe request, and a time period associated with the request (e.g., reduceprocessor frequency to 2.13 GHz at 7 p.m. for six hours). The server 160may also validate the request and lower the processor frequency.Requests may be in the form of an API call that is received by API 162hosted on server 160.

Virtual machines 170A-B may include a guest OS, guest memory, a virtualCPU (VCPU), virtual memory devices (VMD), and virtual input/outputdevices (VI/O). For example, virtual machine 170A may include guest OS196A, guest memory 195A, a virtual CPU 190A, a virtual memory devices192A, and virtual input/output device 194A. Guest memory 195A mayinclude one or more memory pages. Similarly, virtual machine 170B mayinclude guest OS 196B, guest memory 195B, a virtual CPU 190B, a virtualmemory devices 192B, and virtual input/output device 194B. Guest memory195B may include one or more memory pages. Each virtual machine 170A-Bmay also include a power consumption profile 191A-B respectively. In anexample, the power consumption profile 191A-B may indicate whether thevirtual machine 170A-B can be provisioned on a host 110 that allowsfrequency scaling. Additionally, the power consumption profile 191A-Bmay indicate acceptable frequency ranges, power levels, or otheroperation parameters for the virtual machine 170A-B. In another example,the power consumption profile 191A-B may indicate whether the virtualmachine 170A-B may be migrated to different hosts. Similarly, theindication whether a virtual machine 170A-B may be migrated to differenthosts may be included in the request received from the cloud user.

The hypervisor 180 may manage host memory 184 for the host operatingsystem 186 as well as memory allocated to the virtual machines 170A-Band guest operating systems 196A-B such as guest memory 195A-B providedto guest OS 196A-B. Host memory 184 and guest memory 195A-B may bedivided into a plurality of memory pages that are managed by thehypervisor 180. Guest memory 195A-B allocated to the guest OS 196A-B maybe mapped from host memory 184 such that when a guest application 198A-Buses or accesses a memory page of guest memory 195A-B, the guestapplication 198A-B is actually using or accessing host memory 184.

In an example, a virtual machine 170A may execute a guest operatingsystem 196A and run applications 198A-B which may utilize the underlyingVCPU 190A, VIVID 192A, and VI/O device 194A. One or more applications198A-B may be running on a virtual machine 170A under the respectiveguest operating system 196A. A virtual machine (e.g., VM 170A-B, asillustrated in FIG. 1) may run on any type of dependent, independent,compatible, and/or incompatible applications on the underlying hardwareand OS. In an example, applications (e.g., App 198A-B) run on a virtualmachine 170A may be dependent on the underlying hardware and/or OS 186.In another example embodiment, applications 198A-B run on a virtualmachine 170A may be independent of the underlying hardware and/or OS186. For example, applications 198A-B run on a first virtual machine170A may be dependent on the underlying hardware and/or OS 186 whileapplications (e.g., application 198C-D) run on a second virtual machine(e.g., VM 170B) are independent of the underlying hardware and/or OS186A. Additionally, applications 198A-B run on a virtual machine 170Amay be compatible with the underlying hardware and/or OS 186. In anexample embodiment, applications 198A-B run on a virtual machine 170Amay be incompatible with the underlying hardware and/or OS 186. Forexample, applications 198A-B run on one virtual machine 170A may becompatible with the underlying hardware and/or OS 186A whileapplications 198C-D run on another virtual machine 170B are incompatiblewith the underlying hardware and/or OS 186. In an example embodiment, adevice may be implemented as a virtual machine (e.g., virtual machine170A-B).

The cloud computer system 100 may include one or more hosts 110A-C ornodes. Each host 110A-C may in turn include one or more physicalprocessors (e.g., CPU 120A-D) communicatively coupled to memory devices(e.g., MD 130A-C) and input/output devices (e.g., I/O 140A-C). Each host110A-C may be a computer, such as a physical machine and may include adevice, such as hardware device. In an example, a hardware device mayinclude a network device (e.g., a network adapter or any other componentthat connects a computer to a computer network), a peripheral componentinterconnect (PCI) device, storage devices, disk drives, sound or videoadaptors, photo/video cameras, printer devices, keyboards, displays,etc. Virtual machines 170A-B may be provisioned on the same host (e.g.,host 110A) or different hosts. For example, VM 170A and VM 170B may bothbe provisioned on host 110A. Alternatively, VM 170A may be provided onhost 110A while VM 170B is provisioned on host 110B.

As used herein, physical processor or processor 120A-D refers to adevice capable of executing instructions encoding arithmetic, logical,and/or I/O operations. In one illustrative example, a processor mayfollow Von Neumann architectural model and may include an arithmeticlogic unit (ALU), a control unit, and a plurality of registers. In afurther aspect, a processor may be a single core processor which istypically capable of executing one instruction at a time (or process asingle pipeline of instructions), or a multi-core processor which maysimultaneously execute multiple instructions. In another aspect, aprocessor may be implemented as a single integrated circuit, two or moreintegrated circuits, or may be a component of a multi-chip module (e.g.,in which individual microprocessor dies are included in a singleintegrated circuit package and hence share a single socket). A processormay also be referred to as a central processing unit (CPU).

As discussed herein, a memory device 130A-D refers to a volatile ornon-volatile memory device, such as RAM, ROM, EEPROM, or any otherdevice capable of storing data. As discussed herein, I/O device 140A-Crefers to a device capable of providing an interface between one or moreprocessor pins and an external device capable of inputting and/oroutputting binary data.

Processors 120A-D may be interconnected using a variety of techniques,ranging from a point-to-point processor interconnect, to a system areanetwork, such as an Ethernet-based network. Local connections withineach node, including the connections between a processor 120A-D and amemory device 130A-D may be provided by one or more local buses ofsuitable architecture, for example, peripheral component interconnect(PCI).

FIG. 2 illustrates a flowchart of an example method 200 for powerconsumption optimization on the cloud in accordance with an exampleembodiment of the present disclosure. Although the example method 200 isdescribed with reference to the flowchart illustrated in FIG. 2, it willbe appreciated that many other methods of performing the acts associatedwith the method 200 may be used. For example, the order of some of theblocks may be changed, certain blocks may be combined with other blocks,and some of the blocks described are optional. The method 200 may beperformed by processing logic that may comprise hardware (circuitry,dedicated logic, etc.), software, or a combination of both.

The example method 200 includes storing a power consumption profile of avirtual machine provisioned on a host (block 210). For example, powerconsumption profile 191A of virtual machine 170A may be stored in memory(e.g., host memory 184 and/or memory device 130A-D) associated with thehost (e.g., host 110A) that the virtual machine 170A is provisioned onto run at a processor frequency state. In an example, a cloud user mayprovide the power consumption profile 191A associated with virtualmachine 170A to a cloud provider through a server 160. Then, the servermay receive a request to lower a processor frequency for the virtualmachine to a reduced processor frequency state, the request havingrequest criteria indicating a time duration (block 220). For example,after the virtual machine 170A is provisioned on host 110A, the server160 may receive a request from a cloud user to lower a processorfrequency (e.g., frequency of CPU 120A) from an original processorfrequency state to a reduced frequency state for the virtual machine170A. The request may have request criteria indicating a time durationassociated with the request. In an example, requests to lower theprocessor frequency may be requests to reduce the power state or P-stateof the virtual machine 170A and/or application 198A-B.

A power state or P-state is a voltage-frequency pair that set the speedand power consumption of a processor. For example, when the operatingvoltage of the processor is lower, the power consumption is also lower.Additionally, frequency may be lowered in tandem with the voltage, suchthat lower frequency results in slower computation. Different hosts maysupport different ranges of P-states. For example, a host may supportP-states P0 to P3 (e.g., host is capable of operating the processor atP-states P0 to P3). In an example, P-states may be numbered startingfrom P0 (the highest performance setting) and may go to P15 (the lowestpossible processor frequency). P0 may consume the maximum power, andhave the maximum performance. Each successive P-state may consume lesspower, but respectively have less performance. For example, theperformance and power consumption of P0 is greater than P1 (i.e.,P0>P1). Similarly, P1>P2, and so on such that the performance, processorfrequency, and power consumption of P(n−1)>Pn. In an example, P0 may be2.50 GHz at 1.425V, P1 may be 2.31 GHz at 1.4125V, P2 may be 2.13 GHz at1.1875V, P3 may be 1.83 GHz at 1.262V, P4 may be 1.52 GHz at 1.1625V, P5may be 1.22 at 1.0625 V, P6 may be 0.91 GHz at 0.9375V, etc. In otherexamples, the P-states may have different incremental ranges, such as P0to P4. Additionally, the P-states for each host 110 may be differentdepending on the hardware and/or firmware on the host 110. For example,P1 on host 110A may be a different frequency-voltage pair than P1 onhost 110B. In an alternative example, P0 may be the lowest frequency andperformance and Pn may be the highest frequency and performance.

The server may validate the request criteria (block 230). In an example,the server 160 may validate the request criteria by checking whether thehost 110A and the associated processor (e.g., CPU 120A) are capable ofoperating at the requested frequency. For example, CPU 120A may becapable of operating between P-states P0 (e.g., 2.50 GHz) to P3 (e.g.,1.83 GHz), and thus a request to lower the process frequency below 1.83GHz may not be possible on host 110A. In such an event, the server 160may determine that the request criteria fails validation. In an example,when the request fails validation, the server 160 may reject therequest. For example, the server 160 may send a notification to thecloud user that the request has been rejected. In an example, the clouduser may receive a notification from the cloud provider that the requesthas been rejected.

In another example, validating the request criteria may include checkingthe requested time frame or time duration for lowering the processorfrequency against the current host processor schedule. For example, host110A may have a predetermined processor schedule to operate at P-stateP0 from 5 a.m. to 10 p.m. eastern time and then switch to P-state P1from 10 p.m. to 5 a.m. the following day. Thus, a request to change theP-state below P0 between the hours of 5 a.m. and 10 p.m. may be deniedbecause the requested time frame conflicts with the pre-existingschedule on host 110A.

In another example, validating the request criteria may includecomparing the request to other requests received by different tenants(e.g., virtual machine 170B) provisioned on host 110A. For example, theserver 160 may deny requests due to previous commitments from otherrequests (e.g., the P-state or time frame of the current requestconflicts with those of a previously received request). In an example,requests may be handled on a first come-first serve basis. Requests mayalso be prioritized based on power savings. For example, requestsresulting in the largest power savings may be given priority. In anotherexample, requests that are most profitable to the cloud provider may begiven priority. For example, requests with low incentive demands may beprocessed first since the cloud provider would advantageously consumeless power while reducing the cloud credits or incentives it distributesto cloud users.

Then, the server may validate requirement(s) of another tenant on thehost (block 240). For example, the server 160 may determine that othertenants (e.g., virtual machine 170B) on host 110A are not negativelyimpacted by the request. In an example, processor frequency scaling mayaffect all CPU cores on host 110A and tenants residing on the same host110A may be impacted if the processor (e.g., CPU 120A) scales to a lowerfrequency or power-state. For example, if the power consumption profilefor VM 170B indicates that the P-state must be between P0 and P2, thenthe server 160 may deny a request to reduce the processor frequency to1.83 GHz for a power state of P3 because that frequency is outside ofthe frequency ranges of the other tenants (e.g., VM 170B) on host 110A.However, if the request was to reduce the processor frequency from P0 toP1 (e.g., 2.31 GHz), then the server 160 may validate the requirementsindicated by the power consumption profile 191B of VM 170B because thereduced power state is within the acceptable range for the other tenant(e.g., VM 170B).

Next, the server may confirm the request to lower the processorfrequency (block 250). For example, responsive to validating the requestcriteria and requirement(s) of other tenants on the host, the server 160may confirm or accept the request to lower the processor frequency. Inan example, the server 160 may send a confirmation or notification tothe cloud user. Additionally, the server 160 may notify the cloudprovider that the request has been accepted, and the cloud provider mayforward the notification to the cloud user. Then, the server may lowerthe processor frequency to the reduced processor frequency state duringthe time duration (block 260). For example, the server 160 may lower thepower state of the processor (e.g., CPU 120A), thereby lowering thefrequency and power consumption during the requested time duration(e.g., 7 hours), which advantageously conserves system resources byconsuming less power. Additionally, the cloud user may be credited acloud credit for reducing power consumption, which may be used later toincrease CPU performance to a high performance P-state (e.g., P0) whenexperiencing a spike in traffic or a forecasted increase in workload(e.g., release of a new application feature or by adding additionalusers on the application). The cloud credits advantageously provide anincentive to cloud users to conserve energy and allow cloud users toscale-up processor performance in times of need such that the processoris optimized for performance and power consumption throughout the day.

FIGS. 3A, 3B and 3C illustrate a flowchart of an example method 300 forpower consumption optimization in the cloud in accordance with anexample embodiment of the present disclosure. Although the examplemethod 300 is described with reference to the flowchart illustrated inFIGS. 3A, 3B and 3C, it will be appreciated that many other methods ofperforming the acts associated with the method 300 may be used. Forexample, the order of some of the blocks may be changed, certain blocksmay be combined with other blocks, and some of the blocks described areoptional. For example, a cloud user 303 and a cloud provider 305 maycommunicate with an API 162 and virtual machines 170 (e.g., VM_A andVM_B) on a host 186 (e.g., Host_A) to perform example method 300.

In the illustrated example, the cloud user 303 may send a powerconsumption profile 191A for a specific virtual machine 170 (e.g., VM_A)to a cloud provider 305 (blocks 302 and 304). In an example, the powerconsumption profile 191A may indicate whether the virtual machine 170can be provisioned on a host 110 that allows frequency scaling.Additionally, the power consumption profile 191A may indicate acceptablefrequency ranges, power levels, or other operation parameters for thevirtual machine 170. Then, the cloud provider 305 may receive the powerconsumption profile 191A indicating VM_A operating conditions (block306). For example, the power consumption profile 191A may indicate thatfrequency scaling is allowed for VM_A with operational power statesbetween power state P0 and power state P1.

Other tenants may also have virtual machines provisioned on host_A. Inthe illustrated example, VM_B may be provisioned on host_A (block 308).For example, the cloud provider 305 may have provisioned VM_B on host_Abecause the power consumption profile 191B of VM_B indicated thatfrequency scaling is allowed for VM_B. Additionally, the powerconsumption profile 191B of VM_B may indicate that VM_B requires a powerstate of at least P2 (e.g., VM_B should be provisioned on a host with aprocessor power state of P0, P1, or P2). After receiving the powerconsumption profile 191A, the cloud provider 305 may provision VM_A onhost_A in accordance with the profile 191A (blocks 310 and 312). In anexample, the cloud provider 305 may find a host 110 that best matchesthe cloud user's 303 power consumption profile 191A. For example, host_Amay have frequency scaling enabled and may operate at the desired powerstates (e.g., processor frequency ranges) of VM_A, and the cloudprovider 305 may provision VM_A on host_A since the properties of host_Aalign with the requirements of VM_A's power consumption profile. Then,VM_A is provisioned on host_A (block 314). For example, the cloudprovider 305 may instruct a hypervisor 180 to provision VM_A on host_A.In an example, VM_A may run on host_A at a P0 power state (e.g., 2.50GHz) After provisioning, the VM_A may run applications (e.g.,applications 198A-B) on the cloud managed by server 160.

A cloud user 303 may send a request to lower CPU frequency of VM_A frompower consumption state P0 to P1 during the hours of 9 p.m. and 5 a.m.eastern time (blocks 316 and 318). For example, the cloud user 303 mayprovide an employee social network application (e.g., application198A-B) on the cloud for employees to share work documents andparticipate in video conferences at work. The company may experiencereduced traffic on the social network application outside of work hours(e.g., in the evening and into the night until the start of thefollowing workday), and therefore a lower processor frequency (and thuslower power consumption) may be capable of handling the workload for theapplication. Due to the expected decrease in traffic at night, the clouduser 303 may request to lower the CPU frequency during that time period(e.g., between 9 p.m. and 5 a.m. eastern time). In an example, therequest may be an API call that is sent to an API 162 hosted on server160. For example, during runtime, the cloud user 303 using virtualmachines (e.g., VM_A) on a higher clocked CPU (e.g., CPU 120A on Host_A)may issue a new cloud VM API call to the cloud provider 305. The APIcall may be and http request (e.g., GET, POST, PUT, etc.). Then, the API162 may receive the request (block 320). In an example, the request maybe recurring (e.g., request occurs at 8 p.m. every day). Additionally,the request may be a one-time request. The request may include a targetlower CPU frequency (e.g., 2.31 GHz) at a future time (e.g., 9 p.m.) fora specified duration (e.g., 8 hours). The request may also include arange of incentives, such as cloud credits, the cloud user 303 iswilling to accept if the request is honored or confirmed.

In another example, the request may include an indication that virtualmachine (e.g., VM_A) and/or application instances (e.g., applications198A-B) can be migrated to a host 110 with a lower CPU frequency if therequest is not validated for host_A. For example, to reduce powerconsumption and receive an incentive, such as a cloud credit, the clouduser 303 may authorize the cloud provider 305 to migrate the VM_A and/orassociated application instances 198A-B to a different host 110operating at the target CPU frequency (e.g., 2.31 GHz). In an example,after the specified duration, VM_A may be migrated back to host_A suchthat it can continue performing at its original power state after thespecified duration of time in the request.

After receiving the request, the API 162 may compare host_A's operatingCPU frequency with the requested lower CPU frequency (block 322). Forexample, host_A may be capable of operating between P-states P0 and P2(e.g., 2.50 GHz and 2.13 GHz), which may be compared against therequested target frequency of 2.31 GHz associated with P-state P1. Eachtenant (e.g., virtual machine) on host_A may be associated with its ownpower consumption profile. VM_B may have a power consumption profile191B indicating acceptable operation power states of P2 or lower (e.g.,P2 to P0, where P2 is the lowest acceptable performance for VM_B) (block324). For example, the power consumption profile of 191B may indicatethat frequency scaling is allowed and VM_B requires a CPU frequencyrange between 2.50 GHz and 2.13 GHz. Then, the API 162 may compare therequest against power consumption profiles (e.g., power consumptionprofile 191B) of other virtual machines (e.g., VM_B) running on host_A(block 326). For example, the server 160 and/or API 162 may compare therequest against the power consumption profile of VM_B to determinewhether the request conflicts with the power consumption profile 191B ofVM_B.

In the illustrated example, the cloud provider 305 may have a cloudcredit lookup table (block 328). For example, cloud provider 305 maystore acceptable incentive ranges in a cloud credit lookup table thatmay be used to determine whether an incentive request is reasonable. Forexample, the lookup table may indicate the cost differences betweenpower states and/or frequencies. The API 162 may determine if a cloudcredit demand associated with the request is within allowable creditlimits (block 330). For example, the API 162 may determine if the cloudcredit demand is within allowable credit limits defined by the cloudcredit lookup table by comparing the demanded value to the cost figuresin the lookup table. For example, a request to lower CPU frequency fromP0 to P1 may be validated if the incentive request is within the costdifference between P0 and P1.

Then, after validating the request, the API 162 may confirm the request(block 332). For example, if all the request criteria are confirmedagainst the respective parties (e.g., host_A, cloud provider 305,tenants such as VM_B) the API 162 and/or server 160 may confirm or honorthe request. Then, some time may pass (block 334). For example, if therequest was confirmed at 3 p.m., then VM_A may continue operating at itscurrent power state P0 until the requested time (e.g., 9 p.m.) to reducethe frequency. The API 162 may reduce the CPU frequency state of VM_Afrom P0 to P1 at 9 p.m. eastern time (block 336). For example, theserver 160 and/or API 162 may instruct host_A to operate at power stateP1 at 9 p.m. such that the CPU frequency is lowered from 2.5 GHz to 2.31GHz to conserve power. Then, the power state of VM_A is reduced to P1(block 338). Since VM_A is provisioned on host_A, the VM_A executes onthe processor at the lower power state. VM_A may then execute tasks atthe lower CPU frequency state (e.g., frequency associated with powerstate P1) (block 340). As discussed above, the cloud user's 303 employeesocial networking application is utilized less during the evening hours,VM_A may efficiently execute tasks at the lower CPU frequency state dueto the decreased traffic, which advantageously conserves resources byreducing power consumption without negatively impacting theapplication's performance.

More time may pass (block 342). For example, the 8-hour duration between9 p.m. and 5 a.m. associated with the request may pass with host_Aoperating at the reduced P-state. After the time period ends, API 162may increase the CPU frequency state of VM_A from P1 to P0 at 5 a.m.eastern time (block 344). Then, the power state of VM_A is increased toP0 (block 346). Since VM_A is provisioned on host_A, the VM_A executeson the processor at the increased power state P0 (e.g., its originalpower state). VM_A may then execute tasks at the increased or originalCPU frequency state (e.g., frequency associated with power state P0)(block 348). Since the cloud user's 303 social networking applicationfor employees is utilized more frequently during work hours, VM_A may byscaled back up to an optimal performance P-state to execute tasks duringhigh traffic time periods.

Then, the cloud provider 305 may provide a cloud credit to the clouduser 303 (blocks 350 and 352). In an example, a cloud credit may be usedto increase processor performance for a given period of time, whichadvantageously allows a cloud user 303 to improve applicationperformance for more demanding workloads to prevent application downtime and improve an application user's experience. Then, the cloud user303 may receive the cloud credit (block 354). For example, the clouduser 303 may receive and incentive, such as a cloud credit, which may beused to increase performance of VM_A or another virtual machine on thecloud to ensure that application instances are operating at the optimumpower state to conserve resources by reducing power consumption andproviding sufficient application performance to users.

The cloud user may submit another request to lower CPU frequency of VM_Afrom power consumption state P0 to P3 during the same time frame (e.g.,9 p.m. to 5 a.m.) the following day (blocks 356 and 358). In an example,the request may include an indication that VM_A may be migrated to adifferent host 110 to satisfy the target frequency indicated by therequest. Then, API 162 may receive the request with an indication orapproval to migrate VM_A to a different host 110 if the request cannotbe confirmed (block 360). Then, the API 162 may compare host_A'soperating CPU frequency with the requested lower CPU frequency (block362). For example, as discussed above, host_A may be capable ofoperating between P-states P0 and P2 (e.g., 2.50 GHz and 2.13 GHz),which may be compared against the requested target frequency of 1.83 GHzassociated with P-state P3.

As discussed above with reference to block 324, VM_B may have a powerconsumption profile 191B indicating acceptable operation power states ofP2 or lower (e.g., P2 to P0, where P2 is the lowest acceptableperformance for VM_B). Then, the API 162 may compare the request againstpower consumption profiles (e.g., power consumption profile 191B) ofother virtual machines (e.g., VM_B) running on host_A (block 364). Forexample, the server 160 and/or API 162 may compare the request againstthe power consumption profile of VM_B to determine whether the requestconflicts with the power consumption profile 191B of VM_B. Since therequested power state P3 conflicts with the power consumption profile191B of VM_B (e.g., P2 to P0, where P2 is the lowest acceptableperformance for VM_B) as well as the operating frequencies of host_A(e.g., P0 to P2), API 162 may reject the request and send rejectionnotifications to the cloud user 303 and the cloud provider 305 (blocks366, 368 and 370). In an example, API 162 may reject the request aftercomparing the request against host_A's operating frequency anddetermining that the requested processor frequency (e.g., 1.83 GHz) isoutside the operational frequency range of host_A. Additionally, the API162 may reject the request solely due to the request being incompatiblewith the power consumption profile 191B of VM_B.

Then, the cloud user 303 may receive the rejection notification (block372). For example, the cloud user 303 may receive a message that therequest has been rejected. Additionally, the cloud provider 305 mayreceive the rejection notification (block 374). In an example, the cloudprovider 305 may forward the rejection notification to the cloud user303. After receiving the rejection notification, the cloud provider 305may search for suitable hosts 110 for VM_A based on the requestedP-state (block 376). For example, the cloud provider 305 may comparehosts 110 against the requested target frequency (e.g., frequencyassociated with P3 power state) to determine which host 110 is the bestmatch for VM_A.

Host_B may be another resource on the cloud and may operate at a P3power state (block 378). For example, host_B may run several virtualmachines at 1.83 GHz and 1.262V associated with the P3 power state.After finding a suitable host, cloud provider 305 may send an updatednotification of migration and a cloud credit to the cloud user 303(blocks 380 and 382). For example, the cloud provider 305 may send amessage to cloud user 303 indicating that VM_A is going to be migratedto a new host 110 along with an appropriate cloud credit for the changein power consumption. Then, the cloud user 303 may receive the updatednotification of migration and the cloud credit associated with themigration (block 384). For example, the cloud user 303 may receive andincentive, such as a cloud credit once the migration is confirmed.

Due to the properties of host_B aligning with the request criteria(e.g., frequency state associated with P3), the cloud provider 305 maymigrate VM_A to host_B at 9 p.m. (blocks 386 and 388). For example, thecloud provider 305 may instruct the hypervisor 180 to migrate VM_A tohost_B. Then, VM_A is migrated to host_B (block 390). For example,hypervisor 180 may migrate VM_A from host_A to host_B. Since VM_A is nowprovisioned on host_B, VM_A executes on the processor at the reducedpower state P3 (e.g., the operational power state of host_B) (block392). As discussed above, the cloud user's 303 employee socialnetworking application is utilized less during the evening hours, andthe cloud user 303 may determine that VM_A can function optimallyoutside of normal working hours at a reduced frequency state of P3instead of a reduced frequency state of P1 from their previous request.For example, VM_A may efficiently execute tasks at the lower CPUfrequency state due to the decreased traffic, which advantageouslyconserves resources by reducing power consumption without negativelyimpacting the application's performance. In another example, VM_A maystay on host_B if host_B increases P-state during the day (e.g.,increases P-state to P0 during the day). Also, VM_A may migrate to a newhost other than host_A or host_B after the time duration associated withthe request ends. For example, VM_A may migrate to host_C at 5 a.m.because host_A has additional tenants (e.g., virtual machines)provisioned on it and therefore no longer has enough available resourcesto run VM_A.

More time may pass (block 394). For example, the 8-hour duration between9 p.m. and 5 a.m. associated with the request may pass with VM_Aoperating at the reduced P-state on host_B. After the time period ends,the cloud provider 305 may migrate VM_A back to host_A at 5 a.m. thefollowing day (blocks 396 and 397). For example, the cloud provider 305may initiate another migration back to host_A thereby increasing the CPUfrequency state of VM_A from P3 to P0 at 5 a.m. eastern time. Then, VM_Ais migrated back to host_A (block 398). In an example, when VM_A ismigrated back to host_A, cloud provider 305 may provide a cloud creditto the cloud user 303, which may used to increase processor performancefor a given period of time, which advantageously allows the cloud user303 to improve application performance for more demanding workloads toprevent application down time and improve an application user'sexperience.

FIG. 4 is a block diagram of an example power consumption optimizationsystem 400 according to an example embodiment of the present disclosure.The power consumption optimization system 400 may include a virtualmachine (VM) 410 provisioned on a host 420, a memory 430, a server 440,and a processor 450 in communication with the memory 430. The processor450 may cause the server 440 to store a power consumption profile 460 ofthe virtual machine 410 provisioned on the host 420. The virtual machine410 provisioned on the host 420 may run at a processor frequency state462. Additionally, the processor 450 may cause the server 440 to receivea request 470 to lower a processor frequency 480 for the virtual machine410 from an original processor frequency state 464 to a reducedprocessor frequency state 466. The request 470 may have request criteria472 indicating a time duration 474 associated with the request 470. Theprocessor 450 may also cause the server 440 to validate the requestcriteria 472, and validate a requirement 490 of at least one othertenant 412 on the host 420. Responsive to validating the requestcriteria 472 and the requirement 490 of the at least one other tenant412 on the host 420, the processor 450 may then confirm the request 470to lower the processor frequency 480. Additionally, the server 440lowers the processor frequency 480 to the reduced processor frequencystate 466 during the time duration 474.

It will be appreciated that all of the disclosed methods and proceduresdescribed herein can be implemented using one or more computer programsor components. These components may be provided as a series of computerinstructions on any conventional computer readable medium or machinereadable medium, including volatile or non-volatile memory, such as RAM,ROM, flash memory, magnetic or optical disks, optical memory, or otherstorage media. The instructions may be provided as software or firmware,and/or may be implemented in whole or in part in hardware componentssuch as ASICs, FPGAs, DSPs or any other similar devices. Theinstructions may be configured to be executed by one or more processors,which when executing the series of computer instructions, performs orfacilitates the performance of all or part of the disclosed methods andprocedures.

It should be understood that various changes and modifications to theexample embodiments described herein will be apparent to those skilledin the art. Such changes and modifications can be made without departingfrom the spirit and scope of the present subject matter and withoutdiminishing its intended advantages. It is therefore intended that suchchanges and modifications be covered by the appended claims.

The invention is claimed as follows:
 1. A system comprising: a virtualmachine (VM) provisioned on a host; a memory; a server; and at least oneprocessor in communication with the memory, wherein the at least oneprocessor causes the server to: store a power consumption profile of thevirtual machine provisioned on the host, the virtual machine provisionedon the host to run at a processor frequency state, receive a request tolower a processor frequency for the virtual machine from an originalprocessor frequency state to a reduced processor frequency state,wherein the request has request criteria indicating a time durationassociated with the request, validate the request criteria, validate atleast one requirement of at least one other tenant on the host,responsive to validating the request criteria and the at least onerequirement of the at least one other tenant on the host, confirm therequest to lower the processor frequency, and lower the processorfrequency to the reduced processor frequency state during the timeduration.
 2. The system of claim 1, wherein the server includes anapplication program interface (API) hosted on the server, the APIreceives the request, validates the request criteria and the at leastone requirement of the at least one other tenant on the host, andconfirms the request.
 3. The system of claim 2, wherein a cloud VM APIcall includes the request.
 4. The system of claim 1, wherein the powerconsumption profile indicates an acceptable processor frequency rangefor the virtual machine.
 5. The system of claim 1, wherein the at leaston processor causes the server to reject a second request having secondrequest criteria responsive to the second request criteria failingvalidation.
 6. The system of claim 1, wherein the at least one processorcauses the server to raise the processor frequency from the reducedprocessor frequency state back to the original processor frequency stateafter the time duration ends.
 7. A method comprising: storing, by aserver, a power consumption profile of a virtual machine provisioned ona host, the virtual machine provisioned on the host to run at aprocessor frequency state; receiving, by the server, a request to lowera processor frequency for the virtual machine from an original processorfrequency state to a reduced processor frequency state, wherein therequest has request criteria indicating a time duration associated withthe request; validating, by the server, request criteria; validating, bythe server, at least one requirement of at least one other tenant on thehost; responsive to validating the request criteria and the at least onerequirement of the at least one other tenant on the host, confirming, bythe server, the request to lower the processor frequency; and lowering,by the server, the processor frequency to the reduced processorfrequency state during the time duration.
 8. The method of claim 7,wherein an application program interface hosted on the server receivesthe request, validates the request criteria and the at least onerequirement of the at least one other tenant on the host, and confirmsthe request.
 9. The method of claim 8, wherein a cloud virtual machine(VM) application program interface (API) call includes the request. 10.The method of claim 7, wherein the virtual machine on the host has apower consumption profile, the power consumption profile indicates anacceptable processor frequency range for the virtual machine.
 11. Themethod of claim 7, further comprising: responsive to second requestcriteria and the at least one requirement of the at least one othertenant on the host failing validation, rejecting a second request. 12.The method of claim 7, wherein validating the at least one requirementof the at least one other tenant includes reviewing at least one powerconsumption profile associated with the respective at least one othertenant with respect to the request.
 13. The method of claim 7, furthercomprising raising, by the server, the processor frequency from thereduced processor frequency state back to the original processorfrequency state after the time duration ends.
 14. The method of claim 7,wherein lowering the processor frequency includes migrating the VM fromthe host operating at a first frequency state to a different host, thedifferent host operating at a second processor frequency state, thesecond processor frequency state is lower than the first processorfrequency state.
 15. The method of claim 14, wherein the secondprocessor frequency state is the same as the reduced frequency state.16. The method of claim 14, further comprising migrating the VM back tothe host operating at the first frequency state when the time durationends.
 17. The method of claim 7, further comprising, providing, by acloud user, the power consumption profile to the server.
 18. Anon-transitory machine readable medium storing code, which when executedby a processor, causes a server to: store a power consumption profile ofa virtual machine provisioned on a host, the virtual machine provisionedon the host to run at a processor frequency state; receive a request tolower a processor frequency for the virtual machine from an originalprocessor frequency state to a reduced processor frequency state,wherein the request has request criteria indicating a time durationassociated with the request; validate the request criteria; validate atleast one requirement of at least one other tenant on the host;responsive to validating the request criteria and the at least onerequirement of the at least one other tenant on the host, confirm therequest to lower the processor frequency; and lower the processorfrequency to the reduced processor frequency state during the timeduration.
 19. The non-transitory machine readable medium of claim 18,wherein an API hosted on the server receives the request, validates therequest criteria and the at least one requirement of the at least oneother tenant on the host, and confirms the request.
 20. Thenon-transitory machine readable medium of claim 19, wherein a cloud VMAPI call includes the request.